This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. We are applying parallel computing techniques to the spectral simulations and fittings of slow motional ESR data. We are planning on installing a new cluster of 16-18 nodes to implement the parallel computing tasks. This will meet the increasing computational challenges we are facing when our slowly relaxing local structure (SRLS) model is applied to more complex biological systems, such as anisotropic lipid membranes and protein either/both diffusion tilts or/and cage tilts. It will also allow us to include more dynamic modes to better approximate the rotational dynamics in these systems. We are now testing our parallelized codes on a number of existing clusters on campus, which will help us to decide what kind of cluster best meets our special needs, contingent on the availability of suitable funding sources.